1. Field of Invention
The present invention relates to an anti-freezing apparatus. More particularly, the present invention relates to a PCV anti-freezing apparatus for a two-cylinder engine.
2. Description of Related Art
Generally in a Blow-by system, usually un-burnt gas in a combustion chamber flows into an intake manifold through a head cover for recycling. When the intake manifold is exposed to a severe cold atmosphere (e.g. about −35° C.), moisture within the Blow-by gas may be condensed and frozen into ice by the cold air at inside and outside of a PCV nipple (Positive Crankcase Ventilation nipple) and thus the PCV nipple may be blocked.
For solving the above problem, referring to FIG. 3, it is proposed to change material of a PCV nipple 120 from steel to plastic for preventing heat transfer to an aluminum intake manifold 110 and also, for preventing freezing on an end of the nipple 120 by cold air, size of the nipple 120 is enlarged.
That is, the size of the nipple 120 is enlarged for preventing freezing on the end A of the nipple 120 by contacting of blow-by gas with cold air, and material of the PCV nipple 120 is changed from steel to plastic for preventing freezing B by heat transfer.
However, although the size of the nipple is enlarged and material of the PCV nipple is changed, the blow-by gas is spread at the end of the PCV nipple and warm oil mist meets to cold air to generate moisture and thus quantity of heat of the generated moisture is relatively small to easily condensate.
That is, dew may be generated at the end of the nipple according to vehicle operation condition and then be freezed.
In the case of two-cylinder engine, oil in the blow-by gas tends to flow into one cylinder according to intake air flow direction.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.